1. Field of the Invention
The present invention relates to a bobbin switching device for winding units of an automatic winder. Spinning bobbins are supplied to winding positions of a number of winding units arranged in parallel with each other and at the same time, empty bobbins are ejected by the bobbin switching device.
2. Prior Art
A conventional bobbin switching device of this kind has been known from the disclosure of Japanese Patent Application Laid-Open No. 69370/1984. This bobbin switching device will be described hereinbelow with reference to FIGS. 4 and 5. In FIG. 4, reference character U denotes a number of winding units disposed at fixed intervals in a lateral direction in front and in the rear as viewed in paper; 1, a bobbin supply conveyor which runs along the units U; 2, an empty bobbin eject conveyor which runs along the units U; and 3, a bobbin switching device arranged between both the conveyors 1 and 2. The bobbin supply conveyor 1 transports a bobbin 4 erected on a tray 5. A peg 7 is stood upright on the tray 5 in the form of a hollow disk through a shoulder 6, the bobbin 4 is placed in an upright attitude on the shoulder 6 through a lower end of a take-up tube 8 of the bobbin inserted into the peg 7, a through hole 10 to communicate a hollow portion in the tray 5 with a center hole 9 of the take-up tube 8 is provided at the end of the peg 7, and the bobbin 4 has its yarn end Y found and is hung into the center hole 9. The bobbin supply conveyor 1 and the empty bobbin eject conveyor 2 are arranged at positions different in level, and the bobbin switching device 3 is provided therebetween so as to provide oblique communication with each other. The bobbin 4 is carried to a winding position 11 in the bobbin supply device 3 by the bobbin supply conveyor 1, wound on a package (not shown) by the winding unit U, ejected in the form of an empty take-up tube 8, and carried by the bobbin eject conveyor 2.
The bobbin switching device 3 will be described in detail. In FIG. 5, first and second guide plates 13 and 14 (which form a passage 12 in which the tray 5 is transferred between both the conveyors 1 and 2) are secured to the winding unit U. A rotatable inclined disk 15 forms the lower surface of a passage 12a on the taking-in side, and a bottom plate 16 forms the lower surface of a passage 12b on the eject side. The bobbin supply conveyor 1, the inclined disk 15, the bottom plate 16 and the bobbin eject conveyor 2 form substantially the same plane continuous to each other, and a part of the inclined disk 15 is in contact with the bobbin supply conveyor 1 and applied with a turning force in a direction as indicated by an arrow a about a shaft 17. The bobbin supply conveyor 1 is further provided with a third guide plate 18 to guide some of the trays 5 being transported in a direction as indicated by an arrow b by the conveyor 1 into the passage 12a on the taking-in side and cause the remaining trays 5 to pass.
A stopper 20 having a free roller 19 at the end thereof is pivoted about a shaft 21, and is urged to be rotated in a direction as indicated by an arrow c by means of a spring 22 and comes into contact with a pin 23 to suppress said rotation. When the stopper 20 is in contact with the pin 23, a convex portion 25 of the stopper defines a bobbin standby position 24 at which the passage 12 is narrower than the outside diameter of the shoulder 6 of the tray 5. Consequently, a tray 5 which has been guided by the bobbin supply conveyor 1 into the passage 12a on the taking-in side is temporarily stopped at the standby position 24, and two trays 5 are thereby maintained within the passage 12a on the taking-in side.
An eject lever 26 is pivoted about a shaft 28 on the second guide plate 14. The eject lever 26 has a concave portion 31 capable of embracing and holding the shoulder 6 of the tray 5 at the second bended portion of the passage 12, that is, at the winding position 11, and the other side thereof constitutes an arcuate roller support edge 32 about said shaft 28. The shaft 28 of the eject lever 26 is turned by a locking arm which is reciprocated by a push rod 44 which vertically moves by a cam row 43.
The winding position 11 is set on the inclined disk 15, and a plurality of arcuate through holes 34 about the shaft 17 are provided in a portion of the inclined disk 15 corresponding to a portion where the center of the peg 7 passes. As shown in FIG. 4, a nozzle 35 for jetting compressed air toward the through hole 34 is provided at the position where the center position of the peg 7 passes and is located at a level further below the through hole 34. A valve 38 controlled to be opened and closed by a lever 37 is provided between the nozzle 35 and an air hose 36 for supplying air. Air supplied by the hose 36 passes through the valve 38 by the turning of the lever 37 resulting from the turning of a shaft 39, enters a hollow portion of the tray 5 through the through hole 34 of the inclined disk 15 from the nozzle 35, passes through the through hole 10 of the peg 7, flows into the center hole 9 of the take-up tube 8 and upwardly blows the yarn end Y hung into the center hole 9. The blown yarn end Y passes through the yarn guide 40 secured to the winding unit U, is attracted and held by a suction pipe 41 which stands-by at an upper location and is joined with the yarn end on the package side not shown and the yarn is wound. The shaft 39 of the lever 37 is also turned by a locking arm which is reciprocated by a push rod 45 which is vertically moved by the cam row 43.
The operation of the bobbin switching device 3 will be described hereinbelow. First, in a normal winding state shown in FIG. 5, one tray 5 and two trays 5 are positioned at the winding position 11 and at the standby position 24 in the passage 12a on the taking-in side, respectively. At that time, a first tray 5a at the winding position 11 is supported by and stopped in the concave portion 31 of the eject lever 26 with respect of the shoulder thereof while a second tray 5b at the standby position 24 is caused to contact the convex portion of the stopper 20 with the shoulder 6 thereof and suppressed in its feed by the disk 15.
When the winding operation of the bobbin 4 on the first tray 5a from the aforesaid state is completed, the shaft 28 is turned at a fixed angle by the cam row 43 of the winding unit U. Thereby, the eject lever 26 is turned leftward as shown in FIG. 6 while holding the first tray 5a within the concave portion 31 and ejects the first tray 5a from the passage 12b on the eject side onto the bobbin eject conveyor 2. With the rotation of the eject lever 26, a roller support edge 32 of the eject lever 26 comes into contact with the free roller 19 of the stopper 20 to move leftward the convex portion 25 of the stopper 20. Accordingly, the second tray 5b is released from the convex portion 25, is sent by the always rotating inclined disk 15 due to the driving force resulting from the friction from the bobbin supply conveyor 1 and comes into contact with and stops at the roller support edge 32 of the eject lever 26.
When the eject lever 26 is returned to its original position, the stopper 20 returns to its original position shown in FIG. 5, and the second tray 5b stopped at the roller support edge 32 is sent into the concave portion 31 of the eject lever 26, that is, to the winding position 11. At the same time, the shaft 39 shown in FIG. 4 rotates to release the valve 38, and compressed air from the nozzle 35 is jetted through the through hole 34 of the inclined disk 15 and the through hole 10 of the peg 7 to blow up the yarn end Y of the bobbin 4 so that the yarn end Y is held by the suction pipe 41 to start winding operation.
In the bobbin switching device 3 explained in connection with the prior art, as shown in FIG. 4, the inclined disk 15 runs on the bobbin supply conveyor 1 and obtains the turning force by the friction so that the disk 15 always rotates. In order that the bobbin is supplied and at the same time the empty bobbin is ejected as shown in FIGS. 5 and 6, it is necessary to positively and quickly transport the bobbin at the standby position 24 to the winding position 11. Yarn finding operation of bobbin fails unless the bobbin enters a predetermined winding position 11. In view of this, the always rotating inclined disk 15 is preferable, and the adjacent bobbin supply conveyor 1 is utilized. However, the belt end of the bobbin supply conveyor 1 is pressed by the inclined disks of a number of spindles, and there is the problem in that the belt of the bobbin supply conveyor 1 tends to wear. There is a further problem in that since the bottom surface of the plastic tray 5 is normally stopped and rubbed by the inclined disk 15, the bottom surface of the tray 5 becomes worn.
The present invention has been accomplished in view of the problems noted above with respect to prior art.